Abstract: The subject of the invention is a cast part with high static mechanical strength, and for fatigue and hot creep, made of aluminum alloy of composition: Si: 3-11%, preferably 5.0-9.0% Fe<0.50%, preferably <0.30%, preferably still <0.19% or even 0.12% Cu: 2.0-5.0%, preferably 2.5-4.2%, preferably still 3.0-4.0% Mn: 0.05-0.50%, preferably 0.08-0.20% Mg: 0.10-0.25%, preferably 0.10-0.20% Zn: <0.30%, preferably <0.10% Ni: <0.30%, preferably <0.10% V: 0.05-0.19%, preferably 0.08-0.19%, preferably still 0.10-0.19% Zr: 0.05-0.25%, preferably 0.08-0.20% Ti: 0.01-0.25%, preferably 0.05-0.20% other elements <0.05% each and 0.15% in total, the rest aluminum. It more particularly relates to cylinder heads for supercharged diesel or petrol internal combustion engines.

Abstract: The subject of the invention is a cast part with high static mechanical strength, and high hot creep strength, made of aluminum alloy of chemical composition: Si: 0.02-0.50%, Fe: 0.02-0.30%, Cu: 3.5-4.9%, Mn: <0.70%, Mg: 0.05-0.20%, Zn <0.30%, Ni: <0.30%, V: 0.05-0.30%, Zr: 0.05-0.25%, Ti: 0.01-0.35%, other elements in total <0.15%; and 0.05% each, the remainder being aluminum. It more particularly relates to cylinder heads for supercharged diesel or gasoline internal combustion engines.

Abstract: The subject of the invention is a cast part with high static mechanical strength, and for fatigue and hot creep, made of aluminum alloy of composition: Si: 3-11%, preferably 5.0-9.0% Fe <0.50%, preferably <0.30%, preferably still <0.19% or even 0.12% Cu: 2.0-5.0%, preferably 2.5-4.2%, preferably still 3.0-4.0% Mn: 0.05-0.50%, preferably 0.08-0.20% Mg: 0.10-0.25%, preferably 0.10-0.20% Zn: <0.30%, preferably <0.10% Ni: <0.30%, preferably <0.10% V: 0.05-0.19%, preferably 0.08-0.19%, preferably still 0.10-0.19% Zr: 0.05-0.25%, preferably 0.08-0.20% Ti: 0.01-0.25%, preferably 0.05-0.20% other elements <0.05% each and 0.15% in total, the rest aluminum. It more particularly relates to cylinder heads for supercharged diesel or petrol internal combustion engines.

Abstract: Cast part with high creep resistance, made of an alloy with a composition comprising (% by weight): Si: 5-11 Fe<0.6 Mg: 0.15-0.6 Cu: 0.3-1.5 Ti: 0.05-0.25 Zr: 0.05-0.25 Mn<0.4 Zn<0.3 Ni<0.4 other elements<0.10 each and 0.30 total, remainder aluminium.

Abstract: The invention concerns a safety component with high mechanical strength and good ductility, moulded in Al—Si alloy consisting (in wt. %) of: Si: 2-11; Mg: 0.3-0.7; Cu: 0.3 0.9; other elements <1 each and <2 in total, the rest being aluminium, and solution heat treated, tempered and hardened resulting in Brinell hardness of more than 125. The invention also concerns a safety component with high mechanical resistance and good ductility, moulded in Al—Si alloy consisting (in wt. %) of: Si: 2-6; Mg: 0.3-0.7; Fe <0.20; other elements <0.3 each and <1 in total; the rest being aluminium; solution heat treated, hardened and tempered resulting in a quality index Q=Rm+log A>485 MPa.

Abstract: This invention relates to a eutectic or hypereutectic aluminium-silicon alloy product suitable for thixoforming, comprising (by weight) 10 to 30% silicon and, if applicable, copper (<10%), magnesium (<3%), manganese (<2%), iron (<2%), nickel (<4%), cobalt (<3%) and other elements (<0.5% each and 1% in total), the microstructure of which is composed of primary silicon crystals, equiaxed type aluminium dendrites less than 4 mm in size and a eutectic composed of eutectic silicon grains and eutectic aluminium grains less than 4 mm in size.

Abstract: A metal alloy mass of a defined porosity for forming in the semi-solid state. When the porosity is measured by cooling in ambient air from a temperature corresponding to a liquid fraction ratio between 30 and 70% to the ambient temperature, the mass has a porosity ratio, measured by image analysis, between 2 and 20%, and preferably between 3 and 8%. Alternatively, when the gassing level is measured by a solidification test under 80 hPa, the mass has a volumetric porosity ratio between 3 and 50% and preferably between 4 and 25%.

Abstract: The invention relates to an aluminum alloy for thixoforming with the composition (by weight): Si: 5%-7.2% Cu: 1%-5% Mg<1% Zn<3% Fe<1.5% other elements<1% each and<3% in total, with % Si<7.5-% Cu/3, which, when reheated to the semisolid state to the point at which a liquid fraction ratio between 35 and 55% is obtained, has an absence of non-remelted polyhedral silicon crystals.

Abstract: A blank is prepared of a thixotropic metal material and the blank is reheated to a semi-solid state to obtained a liquid fraction corresponding to a desired viscosity for shaping, while determining the power used in the reheating. The reheated blank is transferred to a forging press including a forging stamp or to a pressure die casting machine including an injection plunger. The resistance of the material to the forging stamp or the injection plunger is determined and defined as a set point value and the blank is shaped by the forging stamp or pressure die casting machine. A subsequent blank of the thixotropic metal material is shaped by the forging press or the pressure die casting machine, and the power used in reheating is regulated to maintain the resistance at the set point value.

Abstract: A pattern of an aluminum alloy article made from a foam of an organic substance. The pattern is immersed in a mold of dry sand containing no binder. The mold is filled with molten aluminum alloy from a feeder zone and the alloy is allowed to solidify, thereby creating at least one critical zone in which solidification takes place last. Before the solidified fraction of metal exceeds 40% by weight, an isostatic gas pressure is applied to the mold. The aluminum alloy has a solidification range higher than 30.degree. C. and a ratio R of the distance between the feeder zone and at least one critical zone to half the means thickness of the article over this distance is greater than 10. The isostatic gas pressure being applied is between 0.1 and 0.5 MPa.

Abstract: An improvement to the process for the lost-foam casting of metal articles. According to the process, the casting takes place under a controlled pressure which initially increases at a rate between 0.003 and 0.3 MPa for a first period of at most 5 seconds from the begining of the rise in pressure. The pressure then increases during a second period at a rate higher than the rate of increase during the first period, until the maximum desired pressure is attained.

Abstract: An improvement in the lost foam casting process in which a foam pattern of a part to be cast is immersed in a dry sand mold and the mold is filled with molten metal in order to burn the pattern. According to the improvement, after filling but before the solidified fraction of metal exceeds 40% by weight, an isostatic gas pressure which increases at a predetermined and substantially constant rate to a predetermined maximum value is applied to the mold and maintained at the maximum value until solidification occurs. The rate of increase of pressure is determined as a function of the granulometry of the sand and depth of immersion of the pattern, to cause due to a temporary lag in pressure transmittal through the sand, a rapid and temporary overpressure of the molten metal relative to the sand at the sand/metal interface. The overpressure reaches a maximum value of 0.001 to 0.030 MPa at the beginning of the pressure application and declines as the applied pressure further increases.

Abstract: An organic foam pattern of the article to be cast is immersed in a dry sand mold containing no binder, the mold is filled with molten aluminum or aluminum alloy which replaces the foam and gradually solidifies, and an increasing isostatic gas pressure is simultaneously applied to the mold and to the aluminum or aluminum alloy after filling of the mold is complete. The isostatic gas pressure rises to a maximum value higher than 1.5 MPa and up to 10 MPa, and results in cast articles having improved mechanical characteristics and, in particular, better resistance to fatigue.